 /* 通配符选择器：匹配所有的HTML标签 */
 * {
     margin: 0;
     padding: 0;
 }

 body {
     color: #333;
 }

 img {
     vertical-align: middle;
 }

 .header {
     height: 100px;
 }

 .header-content {
     width: 1120px;
     height: 100%;
     margin: 0 auto;
     display: flex;
     justify-content: space-between;
     align-items: center;
 }

 .logo {
     width: 173px;
     height: 60px;
 }

 .tool-bar {
     display: flex;
 }

 .search-box {
     width: 160px;
     border-bottom: 1px solid #262626;
     margin-left: 20px;
 }

 .tool-bar input {
     width: 130px;
     border: none;
     /* 输入框选中时的边框 */
     outline: none;
 }

 .tool-bar>img {
     margin-left: 20px;
 }

 .tool-bar>a {
     text-decoration: none;
     color: #000;
     padding: 0 10px;
 }

 .tool-bar>a:first-child {
     border-right: 1px solid #dbdbdb;
 }

 .tool-bar img {
     flex-shrink: 0;
     width: 20px;
     height: 20px;
 }

 .menu {
     height: 40px;
     display: flex;
     justify-content: center;
     align-items: center;
     border-bottom: 1px solid #dbdbdb;
     position: relative;
 }

 .menu-item {
     height: 100%;
     line-height: 40px;
     /* width: 100px; */
     margin: 0 20px;
     /* 文本左右居中 */
     text-align: center;
     font-size: 15px;
     border-bottom: 3px solid transparent;
     border-top: 3px solid transparent;
     /* 更改鼠标指针样式 */
     /* default: 默认样式（箭头） */
     /* pointer: 手指 */
     cursor: pointer;
 }

 .submenu {
     height: 280px;
     /* border: 3px solid; */
     background-color: #fff;
     width: 100%;
     position: absolute;
     top: 40px;
     left: 0;
     border-top: 1px solid #383838;
     /* 隐藏标签 */
     display: none;
 }

 .all-products:hover .submenu {
     /* 鼠标悬停时，display: block 会覆盖掉原来的 display: none，标签就不会再隐藏 */
     display: block;
 }

 .menu-item:hover {
     border-bottom: 3px solid #a10000;
     /* border-color: #a10000; */
 }

 .banner {
     height: 666px;
     background-color: cornflowerblue;
     background-image: url("../images/banner01.jpg");
     background-repeat: no-repeat;
     background-size: cover;
     background-position: center;
 }

 /* 网页底部 */
 .service {
     height: 113px;
     display: flex;
     justify-content: center;
     align-items: center;
     border-top: 1px solid #dbdbdb;
 }

 .service-item {
     width: 290px;
     height: 53px;
     border-right: 1px solid #dbdbdb;
     display: flex;
     justify-content: center;
     align-items: center;
 }

 .service-icon {
     width: 53px;
     height: 53px;
     background-image: url("../images/footer-xuebitu.png");
     margin-right: 10px;
 }

 .icon2 {
     background-position: -63px 0px;
 }

 .icon3 {
     background-position: -126px 0px;
 }

 .icon4 {
     background-position: -189px 0px;
 }

 .last-item {
     border-right: none;
 }

 .footer {
     background-color: black;
     color: #fff;
     font-size: 14px;
     padding: 30px 0;
     text-align: center;
     /* height: 87px; */
     /* display: flex;
            flex-direction: column;
            align-items: center;
            justify-content: center; */
 }

 /* 上下左右都居中 */
 .flex-center {
     display: flex;
     justify-content: center;
     align-items: center;
 }

 /* 上下居中，左右两端对齐 */
 .flex-bt {
     display: flex;
     justify-content: space-between;
     align-items: center;
 }